電(dian)磁閥(fa)(fa)（Electromagnetic valve）是用電(dian)磁控(kong)(kong)(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)(de)工業設備，是用來(lai)(lai)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)流體的(de)(de)(de)(de)自動(dong)(dong)化基礎元件(jian)，屬于執行器，并不(bu)限于液壓(ya)、氣動(dong)(dong)。用在工業控(kong)(kong)(kong)制(zhi)(zhi)(zhi)系(xi)統(tong)中調整介(jie)質的(de)(de)(de)(de)方向、流量、速度(du)和(he)其他的(de)(de)(de)(de)參數。電(dian)磁閥(fa)(fa)可(ke)以配合(he)不(bu)同(tong)的(de)(de)(de)(de)電(dian)路來(lai)(lai)實現預(yu)期的(de)(de)(de)(de)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)，而控(kong)(kong)(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)(de)精度(du)和(he)靈活(huo)性都能夠保證。電(dian)磁閥(fa)(fa)有很(hen)多種，不(bu)同(tong)的(de)(de)(de)(de)電(dian)磁閥(fa)(fa)在控(kong)(kong)(kong)制(zhi)(zhi)(zhi)系(xi)統(tong)的(de)(de)(de)(de)不(bu)同(tong)位(wei)置發(fa)揮作用，最常(chang)用的(de)(de)(de)(de)是單向閥(fa)(fa)、安全閥(fa)(fa)、方向控(kong)(kong)(kong)制(zhi)(zhi)(zhi)閥(fa)(fa)、速度(du)調節閥(fa)(fa)等。

電(dian)(dian)(dian)磁閥里有(you)密閉的(de)腔(qiang)，在不(bu)同(tong)位(wei)置開有(you)通(tong)孔(kong)(kong)，每個孔(kong)(kong)連接(jie)不(bu)同(tong)的(de)油管，腔(qiang)中間是(shi)活(huo)塞(sai)，兩面(mian)是(shi)兩塊電(dian)(dian)(dian)磁鐵，哪(na)面(mian)的(de)磁鐵線(xian)圈通(tong)電(dian)(dian)(dian)閥體就會被吸引到(dao)哪(na)邊，通(tong)過(guo)控(kong)制(zhi)閥體的(de)移動來開啟(qi)或關閉不(bu)同(tong)的(de)排(pai)油孔(kong)(kong)，而進油孔(kong)(kong)是(shi)常開的(de)，液壓油就會進入不(bu)同(tong)的(de)排(pai)油管，然后通(tong)過(guo)油的(de)壓力來推動油缸(gang)的(de)活(huo)塞(sai)，活(huo)塞(sai)又帶(dai)動活(huo)塞(sai)桿，活(huo)塞(sai)桿帶(dai)動機(ji)械(xie)裝置。這樣通(tong)過(guo)控(kong)制(zhi)電(dian)(dian)(dian)磁鐵的(de)電(dian)(dian)(dian)流通(tong)斷就控(kong)制(zhi)了機(ji)械(xie)運動。

1、電磁閥從原理上分為三(san)大類：

直動式電磁閥

原理(li)：通電(dian)(dian)(dian)時，電(dian)(dian)(dian)磁線圈產生電(dian)(dian)(dian)磁力(li)(li)把關閉(bi)件從(cong)閥(fa)座上提(ti)起，閥(fa)門打開(kai)；斷電(dian)(dian)(dian)時，電(dian)(dian)(dian)磁力(li)(li)消失，彈簧把關閉(bi)件壓(ya)在閥(fa)座上，閥(fa)門關閉(bi)。

特點：在真空、負壓(ya)、零壓(ya)時能(neng)正常(chang)工作，但通徑一(yi)般不超(chao)過25mm。

分步(bu)直動式(shi)電磁閥

原理：它(ta)是一(yi)種(zhong)直動(dong)和(he)先(xian)(xian)導式(shi)相結合的原理，當入口(kou)與出口(kou)沒有壓(ya)差時(shi)，通(tong)(tong)電(dian)(dian)后，電(dian)(dian)磁力(li)(li)(li)(li)直接把(ba)先(xian)(xian)導小閥(fa)和(he)主(zhu)閥(fa)關閉件依次向(xiang)上提(ti)起，閥(fa)門(men)打(da)開。當入口(kou)與出口(kou)達到啟動(dong)壓(ya)差時(shi)，通(tong)(tong)電(dian)(dian)后，電(dian)(dian)磁力(li)(li)(li)(li)先(xian)(xian)導小閥(fa)，主(zhu)閥(fa)下腔(qiang)壓(ya)力(li)(li)(li)(li)上升(sheng)，上腔(qiang)壓(ya)力(li)(li)(li)(li)下降(jiang)，從而利用壓(ya)差把(ba)主(zhu)閥(fa)向(xiang)上推開；斷(duan)電(dian)(dian)時(shi)，先(xian)(xian)導閥(fa)利用彈簧力(li)(li)(li)(li)或(huo)介(jie)質(zhi)壓(ya)力(li)(li)(li)(li)推動(dong)關閉件，向(xiang)下移動(dong)，使(shi)閥(fa)門(men)關閉。

特點：在零壓差或(huo)真空、高壓時亦能(neng)可*動作，但功率較大，要(yao)求(qiu)必(bi)須水平安裝。

先導(dao)式(shi)電磁閥

原理：通(tong)電(dian)時，電(dian)磁力(li)把先(xian)導(dao)孔(kong)打(da)開(kai)，上(shang)(shang)腔(qiang)室(shi)壓力(li)迅速(su)下(xia)降，在關(guan) 閉(bi)(bi)件(jian)周圍(wei)形(xing)成(cheng)上(shang)(shang)低(di)下(xia)高的壓差，流(liu)體(ti)壓力(li)推(tui)動關(guan)閉(bi)(bi)件(jian)向上(shang)(shang)移動，閥(fa)門打(da)開(kai)；斷電(dian)時，彈(dan)簧(huang)力(li)把先(xian)導(dao)孔(kong)關(guan)閉(bi)(bi)，入口壓力(li)通(tong)過(guo)旁通(tong)孔(kong)迅速(su)腔(qiang)室(shi)在關(guan)閥(fa)件(jian)周圍(wei)形(xing)成(cheng)下(xia)低(di)上(shang)(shang)高的壓差，流(liu)體(ti)壓力(li)推(tui)動關(guan)閉(bi)(bi)件(jian)向下(xia)移動，關(guan)閉(bi)(bi)閥(fa)門。

特點：流體壓力范(fan)圍上限(xian)較高，可任意安(an)裝（需(xu)定制）但必須滿足(zu)流體壓差條件。

2、電磁閥從閥結(jie)構和(he)材料上的(de)不同與原理上的(de)區別(bie)，分為(wei)六(liu)個(ge)分支小類：直(zhi)動(dong)(dong)膜(mo)片(pian)結(jie)構、分步直(zhi)動(dong)(dong)膜(mo)片(pian)結(jie)構、先導(dao)膜(mo)片(pian)結(jie)構、直(zhi)動(dong)(dong)活(huo)塞結(jie)構、分步直(zhi)動(dong)(dong)活(huo)塞結(jie)構、先導(dao)活(huo)塞結(jie)構。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)按照功能(neng)分類：水(shui)用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、低溫(wen)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、燃氣(qi)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、氨(an)用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、氣(qi)體(ti)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、液體(ti)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、微型(xing)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、油(you)用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、直流(liu)電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)等。